RF devices are conventionally charged by plugging them into wall outlets and/or by using batteries. Conventional batteries are charged with a line connection to a standard wall outlet power adapter. Power is continuously drained, limiting usage time, and wall outlets are not always available.
Methods for wirelessly charging RF devices have not been successful due to challenges such as limited available passive RF power and potentially hazardous amounts of power necessary to be transmitted over-the-air to overcome propagation losses. For example, for ambient harvesting, conventional RF harvesters require a high gain antenna (requiring a large surface area) and a high-power transmitter for wireless power transfer.
Further, in conventional power harvesting systems, the power harvester unit is inside the system to power the unit, limiting modularity and increasing the size of the device.
Features and advantages of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the corresponding reference number.